The above-noted prior application discloses a pulsatile flow, synchronous ventricular ejection pump which closely simulates the operation of the natural heart. The prior device has the ability during operation to automatically regulate pumping rate as a function of filling pressure. The present invention adds to this the capability of automatically regulating stroke volume as a function of afterload, thus rendering the invention even closer in operation to the natural heart.
The device of the prior application, while notably satisfactory for its intended purposes involves a center rotary drive shaft for a pumping disc which cyclically compresses and forces blood out of a pair of blood compatible sacs which simulate the left and right ventricles of the heart. The shaft has a partially roofed groove and other features which render it somewhat difficult and costly to machine. The present invention offers a substantial improvement over the prior device by utilization of a simpler and much less expensive drive means for the disc which compresses the two sacs or blood chambers of the pump. All of this is accomplished under the invention without diminishing the operational capabilities of the prior device and in fact, as stated, automatic control of pumping rate and stroke volume responsive to variations in filling pressure and pulmonic and systemic pressure, respectively, are both achieved under the invention whereas, in the prior device, automatic control of pumping rate only as a function of filling pressure is achieved.
It should be understood that the invention may also have applications apart from the cardiovascular system; that is, would be suitable for pumping blood outside of the body in cardiopulmonary bypass hardware, and it may also have industrial applications where automatic response to preload and afterload are desired in conjunction with pulsatile flow.
Other features and advantages of the invention will be recognized by those skilled in the art during the course of the following detailed description .